Portion of a display screen with a graphical user interface



FIG. 1 is a front view of a portion of a display screen with a graphical user interface showing a showing a first embodiment of our invention; and,

FIG. 2 is a front view of a portion of a display screen with a graphical user interface showing a second embodiment of our invention.

The longer-incremented broken lines showing of a portion of a display screen are included for the purpose of illustrating portions of the article; the text and numbers shown in finer-incremented broken lines illustrate portions of the graphical user interface; all broken lines form no part of the claimed design. 

CLAIM The ornamental design for a portion of a display screen with a graphical user interface, as shown and described. 